Motor encoding systems have 3-channel reflective encoders

Avago Technologies, a supplier of analog interface components for communications, industrial and consumer applications, released a three-channel reflective encoder. The AEDR-850x encoders feature built-in interpolation for high-resolution measurement that is useful for a wide range of applications, including closed-loop stepper motors, miniature motors, printers, copiers, card readers, insulin pumps and other types of industrial, consumer and medical equipment.

A standard reflective encoder module contains two digital output channels for direction sensing, with another module required for indexing purposes. For motion feedback applications requiring high-resolution measurement, an external interpolation device had previously been necessary. The Avago AEDR-850x reflective encoder integrates an LED light source, photo-detecting and interpolator circuitry, and the three channels in a single package with a 3.95-mm-by-3.40-mm footprint. With high resolution encoding of 304 lines per inch (12 lines per mm), the modules enable a miniaturization for applications where size and space are primary concerns.

The AEDR-850x encoders offer interpolation of up to 4X and enable various resolution designs by changing the codewheel size. The optical-based modules are significantly less susceptible to EMI compared with Hall Effect devices. With an absolute operating temperature range of -20° C to 85° C, the encoders are suitable for a wide range of commercial and industrial operation environments.

Additional AEDR-850x features include: small surface mount leadless package measuring 3.95 mm by 3.40 mm by 0.95 mm, TTL compatible, allowing outputs to be interfaced directly with most of the signal processing circuitries, factors of 1X, 2X and 4X for interpolation selectable via external pinouts, and a single 5 V supply.